[test] Disable isolated_deinit_main_sync.swift for

hamishknight · hamishknight · commit 072e3aae6e63 · 2024-12-17T21:36:16.000Z
back-deployment

This test relies on `_swift_task_deinitOnExecutor`, which
is only available in newer runtimes.
diff --git a/test/Concurrency/Runtime/isolated_deinit_main_sync.swift b/test/Concurrency/Runtime/isolated_deinit_main_sync.swift
@@ -3,6 +3,7 @@
 // REQUIRES: executable_test
 // REQUIRES: concurrency
 // REQUIRES: concurrency_runtime
+// UNSUPPORTED: back_deployment_runtime
 
 var isDead: Bool = false
 
